March 1972 Popular Electronics
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
This Bulova Accuquartz wristwatch is not the first quartz-controlled wearable timepiece; however, it was the first to be manufactured in the U.S. Interestingly, it is not a fully electronic watch because the quartz crystal stimulates a mechanical tuning fork which ultimately drives the hands. Bulova's first tuning-fork-driven "Accutron" was introduced in 1960. It sported a 360 Hz tuning fork that was stimulated by a pair of electromagnets.
I found a couple nice photos of the Accuquartz on the foro.sincortenohaygloria.com website if you want some close-up views.
First American Made Quartz Watch
Watch at right is Bulova's Accuquartz while one at left is earlier, bulky Swiss-made model selling for $1000.
An advanced quartz crystal wristwatch has been introduced by Bulova into a limited number of Manhattan jewelers at a retail price of $395. This is the first such watch to be miniaturized to traditional wristwatch size and the first to be completely manufactured in the U.S.
The crystal is a subminiature sealed type that oscillates at 32,768 Hz, which is two to four times as great as the crystal frequency in other quartz watches now on the market. The actual frequency of the crystal is divided down by IC circuitry to 341 1/3 Hz to drive a tuning fork. The fork, in turn, drives the hands of the watch as well as the day and date indicators.
The IC used is a single plastic-encapsulated low-threshold CMOS (Complementary Metal Oxide Semiconductor) manufactured to Bulova specs by Intersil, of Cupertino, California.
Energy to power the watch is provided by an aspirin-size power cell, which lasts for about 1 year and must be changed by a jeweler. As for accuracy, the watch can be expected to gain or lose no more than 1 to 2 seconds per week when worn on the wrist.
Posted October 16, 2017